49th Union World Conference on Lung Health: GeneXpert can test stool samples to accurately diagnose TB in children

Science Speaks is covering the 49th Union World Conference on Lung Health in The Hague, Netherlands this week.

THE HAGUE, Netherlands – Tuberculosis in children — disease that responds to first line treatment, as well as drug-resistant strains — can be accurately diagnosed by using existing GeneXpert machines and cartridges to test stool samples for TB bacteria, researchers announced here. Not only can GeneXpert accurately diagnose TB and drug resistance in a fraction of the time it takes to diagnose TB using sputum, Petra de Haas of the KNCV Tuberculosis Foundation said, in a comparison study conducted in Indonesia more TB cases were detected using stool samples than sputum samples.

This finding could revolutionize TB case finding among children, who are notoriously difficult to diagnose, researchers said, citing failures to identify more than 60 percent of children with active TB disease every year. Of the more than one million children who develop TB disease each year, 90 percent go untreated, resulting in almost 240,000 deaths, researchers said.

Young children are usually incapable of producing enough sputum to test for TB, de Haas said. The standard method used to get a sputum sample from a child is painful, invasive, complex and stressful, she said, involving inserting a tube inside a child’s nose and running it down into the stomach to retrieve sputum. This painful procedure usually requires an overnight stay at a hospital and most healthcare facilities don’t have the capacity to conduct this test to begin with, Aimgul Duishekeeva with KNCV said. In her native Kyrgyzstan, only one hospital in the entire country has the equipment to perform this test, she said.

“It is quite painful for the child, and it is painful for the parent to watch even after you have explained it to them,” Duishekeeva said, adding that children cough and vomit during the procedure.

Indonesia and Ethiopia will soon start using this method of TB diagnosis on a larger scale to gain practical experience toward expanded usage. Before the end of this year, health care workers at five large hospitals in Indonesia and 22 labs in Ethiopia will be trained in how to do the test.

“If further testing confirms the preliminary findings in Indonesia and Ethiopia, the potential of this method is enormous,” said Kitty van Weezenbeck, executive director of KNCV. “It would mean that we have a method in our hands that can diagnose TB at the lowest health care level and can bring testing to hundreds of thousands of people. In that way, children can now get a microbiologically confirmed TB diagnosis at primary health centers, where that is currently not possible,” she said.

“Our hope is that by 2020, every child has access to this test and children’s lives will be changed,” de Haas said.